The World Wide Web (also known as the “Web”) and the web pages within the Web are a vast source of factual information. Users may look to web pages to get answers to factual questions, such as “what is the capital of Poland” or “what is the birth date of George Washington.” The factual information included in web pages may be extracted and stored in a fact database.
A fact database may, at times, become internally inconsistent. When a fact database is populated with data, there may be gaps in the data for which the database building module does not have the data to fill. When fact database maintenance operations are performed, data may be modified or removed, resulting in possible data inconsistencies. These internal inconsistencies may diminish the quality of the fact database.